var echo = echo || false;
if (echo) {
	echo.init({
	    offset: 736,
        unload: false,
	    // throttle: 250,
        callback: function (element, op) {
            // element.style.visibility = 'visible'
            // console.log(element, 'has been ', op + ' ok')
        }
	});
}

/**
* 回到顶部
*/
!function(){
	var scroll_top_btn = document.getElementById('scrollUp');
	var timer = null;
	document.onscroll = function(){
		var scroll_top = document.body.scrollTop;
		clearTimeout(timer);
		if (scroll_top >= 50) {
			timer = setTimeout(function(){
				scroll_top_btn.style.display = 'block';
			}, 200);			
		} else {
			timer = setTimeout(function(){
				scroll_top_btn.style.display = 'none';
			}, 200);			
		}
	}

	scroll_top_btn.onclick = function(){
		document.documentElement.scrollTop = document.body.scrollTop = 0;
	};

}();


